/**
 * @file XListView.java
 * @package me.maxwin.view
 * @create Mar 18, 2012 6:28:41 PM
 * @author Maxwin
 * @description An ListView support (a) Pull down to refresh, (b) Pull up to load more.
 * 		Implement IXListViewListener, and see stopRefresh() / stopLoadMore().
 */
package com.sudichina.sudichina.view.customview.xlistview;


import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.ScaleAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;

import com.sudichina.sudichina.R;

public class XListView extends ListView implements OnScrollListener {

	private float mLastY = -1; // save event y
	private Scroller mScroller; // used for scroll back
	private OnScrollListener mScrollListener; // user's scroll listener

	// the interface to trigger refresh and load more.
	private IXListViewListener mListViewListener;
	// -- header view
	private XListViewHeader mHeaderView;
	// header view content, use it to calculate the Header's height. And hide it
	// when disable pull refresh.
	private RelativeLayout mHeaderViewContent;
	private TextView mHeaderTimeView;
	private int mHeaderViewHeight; // header view's height
	private boolean mEnablePullRefresh = true;
	private boolean mPullRefreshing = false; // is refreashing.
	// -- footer view
	private XListViewFooter mFooterView;
	private boolean mEnablePullLoad;
	private boolean mPullLoading;
	private boolean mIsFooterReady = false;

	// total list items, used to detect is at the bottom of listview.
	private int mTotalItemCount;

	// for mScroller, scroll back from header or footer.
	private int mScrollBack;
	private final static int SCROLLBACK_HEADER = 0;
	private final static int SCROLLBACK_FOOTER = 1;

	private final static int SCROLL_DURATION = 400; // scroll back duration
	private final static int PULL_LOAD_MORE_DELTA = 50; // when pull up >= 50px
														// at bottom, trigger
														// load more.
	private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
													// feature.

	
	private int slidePosition, preSlidePosition;
	private int downY;
	private int downX;
	public static View itemView, preItemView;
//	private Scroller scroller;
	private static final int SNAP_VELOCITY = 600;
	private VelocityTracker velocityTracker;
	public static boolean isSlide = false;
	private boolean isResponse = true;
	public static boolean isObstruct = true;
	private int mTouchSlop;
	private RemoveListener mRemoveListener;

	private static Animation scaleHideAnimation;
	private static Animation scaleShowAnimation;
	
	
	
	
	/**
	 * @param context
	 */

	public XListView(Context context) {
		super(context);
		initWithContext(context);
		mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
	}

	public XListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initWithContext(context);
		mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
	}

	public XListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
//		mScroller = new Scroller(context, new DecelerateInterpolator());
		initWithContext(context);
		mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
	}

	private void initWithContext(Context context) {
		mScroller = new Scroller(context, new DecelerateInterpolator());
		// XListView need the scroll event, and it will dispatch the event to
		// user's listener (as a proxy).
		super.setOnScrollListener(this);

		// init header view
		mHeaderView = new XListViewHeader(context);
		mHeaderViewContent = (RelativeLayout) mHeaderView
				.findViewById(R.id.xlistview_header_content);
		mHeaderTimeView = (TextView) mHeaderView
				.findViewById(R.id.xlistview_header_time);
		addHeaderView(mHeaderView);

		// init footer view
		mFooterView = new XListViewFooter(context);

		// init header height
		mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(
				new OnGlobalLayoutListener() {
					@Override
					public void onGlobalLayout() {
						mHeaderViewHeight = mHeaderViewContent.getHeight();
						getViewTreeObserver()
								.removeGlobalOnLayoutListener(this);
					}
				});
	}

	@Override
	public void setAdapter(ListAdapter adapter) {
		// make sure XListViewFooter is the last footer view, and only add once.
		if (mIsFooterReady == false) {
			mIsFooterReady = true;
			addFooterView(mFooterView);
		}
		super.setAdapter(adapter);
	}

	/**
	 * enable or disable pull down refresh feature.
	 * 
	 * @param enable
	 */
	public void setPullRefreshEnable(boolean enable) {
		mEnablePullRefresh = enable;
		if (!mEnablePullRefresh) { // disable, hide the content
			mHeaderViewContent.setVisibility(View.INVISIBLE);
		} else {
			mHeaderViewContent.setVisibility(View.VISIBLE);
		}
	}

	/**
	 * enable or disable pull up load more feature.
	 * 
	 * @param enable
	 */
	public void setPullLoadEnable(boolean enable) {
		mEnablePullLoad = enable;
		if (!mEnablePullLoad) {
			mFooterView.hide();
			mFooterView.setOnClickListener(null);
		} else {
			mPullLoading = false;
			mFooterView.show();
			mFooterView.setState(XListViewFooter.STATE_NORMAL);
			// both "pull up" and "click" will invoke load more.
			mFooterView.setOnClickListener(new OnClickListener() {
				@Override
				public void onClick(View v) {
					startLoadMore();
				}
			});
		}
	}

	/**
	 * stop refresh, reset header view.
	 */
	public void stopRefresh() {
		if (mPullRefreshing == true) {
			mPullRefreshing = false;
			resetHeaderHeight();
		}
	}

	/**
	 * stop load more, reset footer view.
	 */
	public void stopLoadMore() {
		if (mPullLoading == true) {
			mPullLoading = false;
			mFooterView.setState(XListViewFooter.STATE_NORMAL);
		}
	}

	/**
	 * set last refresh time
	 * 
	 * @param time
	 */
	public void setRefreshTime(String time) {
		mHeaderTimeView.setText(time);
	}

	private void invokeOnScrolling() {
		if (mScrollListener instanceof OnXScrollListener) {
			OnXScrollListener l = (OnXScrollListener) mScrollListener;
			l.onXScrolling(this);
		}
	}

	private void updateHeaderHeight(float delta) {

		mHeaderView.setVisiableHeight((int) delta
				+ mHeaderView.getVisiableHeight());
		if (mEnablePullRefresh && !mPullRefreshing) { // 未处于刷新状态，更新箭头
			if (mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
				mHeaderView.setState(XListViewHeader.STATE_READY);
			} else {
				mHeaderView.setState(XListViewHeader.STATE_NORMAL);
			}
		}
		setSelection(0); // scroll to top each time
	}

	/**
	 * reset header view's height.
	 */
	private void resetHeaderHeight() {
		int height = mHeaderView.getVisiableHeight();
		if (height == 0) // not visible.
			return;
		// refreshing and header isn't shown fully. do nothing.
		if (mPullRefreshing && height <= mHeaderViewHeight) {
			return;
		}
		int finalHeight = 0; // default: scroll back to dismiss header.
		// is refreshing, just scroll back to show all the header.
		if (mPullRefreshing && height > mHeaderViewHeight) {
			finalHeight = mHeaderViewHeight;
		}
		mScrollBack = SCROLLBACK_HEADER;
		mScroller.startScroll(0, height, 0, finalHeight - height,
				SCROLL_DURATION);
		// trigger computeScroll
		invalidate();
	}

	private void updateFooterHeight(float delta) {
		int height = mFooterView.getBottomMargin() + (int) delta;
		if (mEnablePullLoad && !mPullLoading) {
			if (height > PULL_LOAD_MORE_DELTA) { // height enough to invoke load
													// more.
				mFooterView.setState(XListViewFooter.STATE_READY);
			} else {
				mFooterView.setState(XListViewFooter.STATE_NORMAL);
			}
		}
		mFooterView.setBottomMargin(height);

		// setSelection(mTotalItemCount - 1); // scroll to bottom
	}

	private void resetFooterHeight() {
		int bottomMargin = mFooterView.getBottomMargin();
		if (bottomMargin > 0) {
			mScrollBack = SCROLLBACK_FOOTER;
			mScroller.startScroll(0, bottomMargin, 0, -bottomMargin,
					SCROLL_DURATION);
			invalidate();
		}
	}

	private void startLoadMore() {
		mPullLoading = true;
		mFooterView.setState(XListViewFooter.STATE_LOADING);
		if (mListViewListener != null) {
			mListViewListener.onLoadMore();
		}
	}
	
	//RemoveListener

	public void setRemoveListener(RemoveListener removeListener) {
		this.mRemoveListener = removeListener;
	}
	
	
	public boolean dispatchTouchEvent(MotionEvent event) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN: {

			Log.e("lg", "dispatchTouchEvent ACTION_DOWN isSlide1111 = " + isSlide);

			addVelocityTracker(event);

			downX = (int) event.getX();
			downY = (int) event.getY();

			slidePosition = pointToPosition(downX, downY);

			if (slidePosition == AdapterView.INVALID_POSITION) {
				return super.dispatchTouchEvent(event);
			}

			if (preItemView != null && preItemView.findViewById(R.id.tv_coating).getVisibility() == View.GONE) {
				itemView = preItemView;
				slidePosition = preSlidePosition;
			} else {
				itemView = getChildAt(slidePosition - getFirstVisiblePosition());
				preItemView = itemView;
				preSlidePosition = slidePosition;
			}

			break;
		}
		case MotionEvent.ACTION_MOVE: {
			if (Math.abs(getScrollVelocity()) > SNAP_VELOCITY || (Math.abs(event.getX() - downX) > mTouchSlop && Math.abs(event.getY() - downY) < mTouchSlop)) {
				isSlide = true;
			}
			break;
		}
		case MotionEvent.ACTION_UP:
			recycleVelocityTracker();
			isObstruct = true;
			break;
		}

		return super.dispatchTouchEvent(event);
	}
	
	public boolean onInterceptTouchEvent(MotionEvent ev) {
		switch (ev.getAction()) {
		case MotionEvent.ACTION_MOVE:
			if (itemView.findViewById(R.id.tv_coating).getVisibility() == View.VISIBLE) {
				isSlide = false;
			} else {
				isSlide = true;
			}
			break;

		default:
			break;
		}
		return super.onInterceptTouchEvent(ev);
	}
	
	
	//dispatchTouchEvent ACTION_DOWN isSlide

//	@Override  dispatchTouchEvent
	public boolean onTouchEvent(MotionEvent ev) {
		
	
		if (isSlide && slidePosition != AdapterView.INVALID_POSITION) {
			addVelocityTracker(ev);
			final int action = ev.getAction();
			switch (action) {
			case MotionEvent.ACTION_MOVE:
				if (isObstruct) {

					if (itemView.findViewById(R.id.tv_coating).getVisibility() == View.VISIBLE && isResponse == true) {

						scaleHideAnimation = new ScaleAnimation(1.0f, 0.0f, 1.0f, 1.0f);
						scaleHideAnimation.setDuration(250);
						scaleHideAnimation.setAnimationListener(new AnimationListener() {

							public void onAnimationStart(Animation animation) {
								isResponse = false;
								isObstruct = false;
							}

							public void onAnimationRepeat(Animation animation) {

							}

							public void onAnimationEnd(Animation animation) {
								isResponse = true;
								itemView.findViewById(R.id.tv_coating).setVisibility(View.INVISIBLE);
								itemView.findViewById(R.id.tv_functions).setClickable(true);
								itemView.findViewById(R.id.tv_functions).setOnClickListener(new OnClickListener() {

									public void onClick(View v) {
										mRemoveListener.removeItem(slidePosition);
									}

								});

							}
						});

						itemView.findViewById(R.id.tv_coating).startAnimation(scaleHideAnimation);

					} else if (itemView.findViewById(R.id.tv_coating).getVisibility() == View.GONE && isResponse == true) {

						scaleShowAnimation = new ScaleAnimation(0.0f, 1.0f, 1.0f, 1.0f);
						scaleShowAnimation.setDuration(250);
						scaleShowAnimation.setAnimationListener(new AnimationListener() {

							public void onAnimationStart(Animation animation) {
								isResponse = false;
								isObstruct = false;
							}

							public void onAnimationRepeat(Animation animation) {

							}

							public void onAnimationEnd(Animation animation) {
								isSlide = false;
								isResponse = true;
								itemView.findViewById(R.id.tv_coating).setVisibility(View.VISIBLE);
							}
						});

						itemView.findViewById(R.id.tv_coating).startAnimation(scaleShowAnimation);
					}
				}
				break;
			case MotionEvent.ACTION_UP:
				isObstruct = true;
				recycleVelocityTracker();
				isSlide = true;
				break;
			}
			return true;
		}
		
		if (mLastY == -1) {
			mLastY = ev.getRawY();
		}

		switch (ev.getAction()) {
		case MotionEvent.ACTION_DOWN:
			mLastY = ev.getRawY();
			break;
		case MotionEvent.ACTION_MOVE:
			final float deltaY = ev.getRawY() - mLastY;
			mLastY = ev.getRawY();
			if (getFirstVisiblePosition() == 0
					&& (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {
				// the first item is showing, header has shown or pull down.
				updateHeaderHeight(deltaY / OFFSET_RADIO);
				invokeOnScrolling();
			} else if (getLastVisiblePosition() == mTotalItemCount - 1
					&& (mFooterView.getBottomMargin() > 0 || deltaY < 0)) {
				// last item, already pulled up or want to pull up.
				updateFooterHeight(-deltaY / OFFSET_RADIO);
			}
			break;
		default:
			mLastY = -1; // reset
			if (getFirstVisiblePosition() == 0) {
				// invoke refresh
				if (mEnablePullRefresh
						&& mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
					mPullRefreshing = true;
					mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
					if (mListViewListener != null) {
						mListViewListener.onRefresh();
					}
				}
				resetHeaderHeight();
			} else if (getLastVisiblePosition() == mTotalItemCount - 1) {
				// invoke load more.
				if (mEnablePullLoad
						&& mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA
						&& !mPullLoading) {
					startLoadMore();
				}
				resetFooterHeight();
			}
			break;
		}
		
		
		
		
		
		
		return super.onTouchEvent(ev);
//		return super.onTouchEvent(ev);
	}

	@Override
	public void computeScroll() {
		if (mScroller.computeScrollOffset()) {
			if (mScrollBack == SCROLLBACK_HEADER) {
				mHeaderView.setVisiableHeight(mScroller.getCurrY());
			} else {
				mFooterView.setBottomMargin(mScroller.getCurrY());
			}
			postInvalidate();
			invokeOnScrolling();
			
			if (mScroller.isFinished()) {
				if (mRemoveListener == null) {
					throw new NullPointerException("RemoveListener is null, we should called setRemoveListener()");
				}

				itemView.scrollTo(0, 0);
			}
		}
		super.computeScroll();
	}
	
	
	//addVelocityTracker
	
	private void addVelocityTracker(MotionEvent event) {
		if (velocityTracker == null) {
			velocityTracker = VelocityTracker.obtain();
		}
		velocityTracker.addMovement(event);
	}

	private void recycleVelocityTracker() {
		if (velocityTracker != null) {
			velocityTracker.recycle();
			velocityTracker = null;
		}
	}
	
	private int getScrollVelocity() {
		velocityTracker.computeCurrentVelocity(1000);
		int velocity = (int) velocityTracker.getXVelocity();
		return velocity;
	}

	public interface RemoveListener {
		public void removeItem(int position);
	}
	
	

	@Override
	public void setOnScrollListener(OnScrollListener l) {
		mScrollListener = l;
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		if (mScrollListener != null) {
			mScrollListener.onScrollStateChanged(view, scrollState);
		}
	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem,
			int visibleItemCount, int totalItemCount) {
		// send to user's listener
		mTotalItemCount = totalItemCount;
		if (mScrollListener != null) {
			mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,
					totalItemCount);
		}
	}
	
	
	
	
	

	public void setXListViewListener(IXListViewListener l) {
		mListViewListener = l;
	}

	/**
	 * you can listen ListView.OnScrollListener or this one. it will invoke
	 * onXScrolling when header/footer scroll back.
	 */
	public interface OnXScrollListener extends OnScrollListener {
		public void onXScrolling(View view);
	}

	/**
	 * implements this interface to get refresh/load more event.
	 */
	public interface IXListViewListener {
		public void onRefresh();

		public void onLoadMore();
	}
}
